Crankcase breather

ABSTRACT

A crankcase ventilation system for an internal combustion engine having a cylinder block that at least partially defines at least one cylinder includes a valve cover configured to be mounted on an individual cylinder head corresponding to an individual cylinder and form a cavity therein. Further a crankcase ventilation opening associated with the valve cover. A crankcase breather incorporated into the valve cover. The crankcase breather includes a breather body, an inlet portion in fluid communication with the cavity of the valve cover, and an outlet portion aligning with the crankcase ventilation opening of the valve cover.

TECHNICAL FIELD

The present disclosure relates to a crankcase ventilation system for aninternal combustion engine, and more particularly to a crankcasebreather used in the crankcase ventilation system.

BACKGROUND

During an engine operation, some combustion gases, generally referred toas crankcase gases or blow-by gases, may leak from an engine cylinderinto a crankcase. The crankcase gases may increase pressure in thecrankcase and also mix with oil particles present in the crankcase. Torelieve the pressure in the crankcase, the crankcase gases are typicallyvented out of the crankcase, e.g., to the atmosphere or recirculatedusing a crankcase ventilation system. Government regulations relating toenvironmental concerns have mandated engine manufacturers for heavy dutyutilities to use engines with the crankcase ventilation system. Suchcrankcase ventilation system may employ an engine crankcase breather forsegregating the oil particles present in the gases, before beingreleased into the atmosphere or recirculated.

U.S. Pat. No. 8,156,926 discloses a filtration system. The filtrationsystem includes a valve lid defining a chamber. The chamber isconfigured to extend substantially in a second direction. The filtrationsystem also includes a filter element associated with a lower portion ofthe chamber. The filtration system further includes a passageway in flowcommunication with the lower portion of the chamber. The passageway isconfigured to provide flow communication for a mixture of oil vapor andcrankcase fumes flowing into the chamber substantially in a firstdirection and substantially upward direction. The first direction isgenerally orthogonal to the second direction. The chamber is configuredsuch that the flow of the mixture into the chamber results in at least aportion of the oil vapor collecting in the filter element, and at leasta portion of the crankcase fumes flowing through the filter element.

SUMMARY

In an aspect, the present disclosure provides a crankcase breatherincorporated into an individual valve cover for an individual cylinder.The valve cover forming a cavity and having a crankcase ventilationopening associated with the valve cover. The crankcase breatherincorporated into the individual valve cover includes a breather body,an inlet portion configured to be in fluid communication with the cavityof the valve cover, and an outlet portion configured to be aligned withthe crankcase ventilation opening of the valve cover.

In another aspect, the present disclosure provides a crankcaseventilation system for an internal combustion engine having a cylinderblock that at least partially defines at least one cylinder includes thevalve cover configured to be mounted on an individual cylinder headcorresponding to an individual cylinder. The valve cover forming acavity therein and the crankcase breather incorporated into the valvecover.

Other features and aspects of this disclosure will be apparent from thefollowing description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an engine;

FIG. 2 illustrates an exploded view of a valve cover and a crankcasebreather;

FIG. 3 illustrates a sectional view of the valve cover with thecrankcase breather;

FIG. 4 illustrates a detailed view of an inlet portion of the crankcasebreather; and

FIG. 5 illustrates a bottom view of the crankcase breather.

DETAILED DESCRIPTION

The present disclosure relates to a crankcase breather used in thecrankcase ventilation system for an internal combustion engine. FIG. 1illustrates an internal combustion engine 100, such as, a compressionignition engine.

Alternatively, the engine 100 may be a spark ignition engine or anatural gas engine of any size, with any number of cylinders, and in anyconfiguration (“V,” in-line, radial, etc.). Further, the internalcombustion engine 100 may operate using a variety of fuels, for example,but not limited to, gasoline, diesel, methane, propane or any otherfuels known in the art. The internal combustion engine 100 may include acylinder block 102 that at least partially defines at least one cylinder104 housing a reciprocating piston (not shown). The internal combustionengine 100 may further include a crankshaft operably coupled to thepistons, such that reciprocation of the pistons within the cylinders 104serves to rotate the crankshaft. The crankshaft may be housed within acrankcase 106 defined, for example, by a lower portion of the cylinderblock 102 and an oil sump 108. The crankcase 106 may be adequatelysealed from the surrounding atmosphere to prevent vapor from the engine100 being expelled directly into the atmosphere.

According to an exemplary embodiment of the present disclosure, acrankcase ventilation system 110 is provided for the internal combustionengine 100. The crankcase ventilation system 110 relieves the pressurein the crankcase 106 due to the crankcase gases or “blow-by gases”. Thecrankcase gases may include soot, unburned fuel, exhaust gases, and/orwater vapor. The crankcase ventilation system 110 is a closed-loopcrankcase ventilation system and may include one or more valve covers112 mounted on an individual cylinder head 113 corresponding to thecylinder of the at least one cylinder 104 and configured to surround andprotects inlet and exhaust valves, an upper part of a push rod, a rockerarm, a fuel injection valve, and the like. Thus crankcase gases may berelieved from the crankcase 106 by way of the valve cover 112, which mayfurther route the crankcase gases towards an oil separator 114, such asa cyclonic separator, to separate oil vapor from the crankcase gases viaan inlet hose 116. The oil separator 114 may be connected to an airintake unit 118, such as an air cleaner, and the oil sump 108 via adisposal hose 120 and a drain line 122, respectively. As it will beapparent to a person having ordinary skill in the art that, the oilseparator 114 decrease an amount of oil entering the air intake unit118.

According to an aspect of the present disclosure, a crankcase breather124 is incorporated into the valve cover 112 for the individual cylinder104 which will be explained in detail in conjunction with FIGS. 2-5. Thecrankcase breather 124 is configured to provide a release path for thecrankcase gases and acts as a pre-oil separator before routing thecrankcase gases into the oil separator 114.

FIG. 2 illustrates an exploded view of the valve cover 112 and thecrankcase breather 124. According to an embodiment of the presentdisclosure, the valve cover 112 includes a body 126 that is formed of aninverted cup-shaped with a top wall 128, a pair of side walls 130, 132,and a pair of end walls 134, 136. The pair of side walls 130, 132 andthe end walls 134, 136 extend from the top wall 128 and joined to form acavity 138. The cavity 138 may be in communication with the crankcase106 via openings in the cylinder head 113 and the cylinder block 102. Inan embodiment, the pairs of side walls 130, 132 and the end walls 134,136 are stamped from a single sheet of metal. Alternatively, the valvecover 112 may be manufactured by a plastic molding .process. Twoperipheral ledges 140 (only one side is shown in FIG. 2) may extend fromeach of the side walls 130, 132 and which are bounded by perimetricflanges 142. The peripheral ledges 140 are substantially perpendicularto the side walls 130, 132, while the perimetric flanges 142 aresubstantially parallel to the side wall 130, 132. Further, a row of oneor more through holes 141 is provided on the peripheral ledges 140 andconfigured to receive fastening members 142 to mount the valve cover 112on the cylinder head 113. For example, as illustrated in FIG. 2, thefastening members 142 may be bolts. Alternatively, the fastening member142 may be a screw, a rivet, a pin, and/or any appropriate fastener forsealingly coupling the valve cover 112 to the cylinder head 113.Furthermore, a seal or gasket (not shown) made of, for example, siliconrubber, is provided between the valve cover 112 and the cylinder head113 to provide both effective sealing and noise-damping. In anembodiment, the body 126 of the valve cover 112 may include a firstrecess 144 and a second recess 146 located along each of the side walls130, 132. The first recess 144 and/or the second recess 146 may beconfigured to provide clearance for fastening members 142 such that thebody 126 does not interfere while installing the fastening members 142.Alternatively, the size and number of recess, such as 144, 146, maydepend on the design and size requirements of the valve cover 112.

According to an embodiment of the present disclosure, the top wall 128of the valve cover 112 may include a crankcase ventilation opening 148associated with the valve cover 112 and in communication with the cavity138 of the valve cover 112. The crankcase breather 124 may include aninlet portion 150 and an outlet portion 152. Upon installation the inletportion 150 is in fluid communication with the cavity 138 and the outletportion 152 of the crankcase breather 124 is configured to align withthe crankcase ventilation opening 148 of the valve cover 112 and receivethe inlet hose 116. The inlet hose 116 may be sealingly secured into theoutlet portion 152 using a threaded adapter 154 and an O-ring seal 156.The threaded adapter 154 is retained within the crankcase ventilationopening 148 which is provided with complementary internal threads.Alternatively, various other known means may be used to sealingly securethe inlet hose 116 with the outlet portion 152 of the crankcase breather124.

According to an embodiment of the present disclosure, the crankcasebreather 124 may include a breather body 158 and a bottom plate 160. Thebreather body 158 may have a two-box form with a breather top wall 162,a first pair of breather side walls 164, and a second pair of breatherside walls 166. The first and second pair of breather side walls 164,166 may extend from the breather top wall 162 and stamped from a singlesheet of metal. The first pair of breather side walls 164 are spacedapart by a first distance D1 larger than a second distance D2 betweenthe second pair of breather side walls 166. A breather peripheral ledge168 may extend from the first and second pair of breather side walls164, 166. The breather peripheral ledges 168 is coupled to the bottomplate 160 using a stable means, such as rivets 169 or adhesive orwelding or brazing, to define a filtration chamber, such that the firstpair of breather side walls 164 and the bottom plate 160 define a firstfiltration chamber 170 and the second pair of breather side walls 166and the bottom plate 160 define a second filtration chamber 172 (aportion of the breather top wall 162 is removed to show the secondfiltration chamber 172). The bottom plate 160 may include ear portions,such as a first and second ear portions 173 extending beyond the inletportion 150 of the crankcase breather 124 to define inlet zones 175within the cavity 138 of the valve cover 112. Further, the bottom plate160 may include apertures 174 which are configured to receive fasteningmembers 176 to secure the crankcase breather 124 within the cavity 138of the valve cover 112.

FIG. 3 illustrates a sectional view of the valve cover 112 with thecrankcase breather 124. As illustrated, a first filter element 177 and asecond filter element 178 may be disposed within the first and secondfiltration chambers 170, 172, respectively. The first and second filterelements 177, 178 may be formed from any appropriate filter material,for example, such that at least a portion of oil vapor may be separatedfrom crankcase gases (shown by arrow heads). The filter elements 177,178 may include a cross-section that may be in the form of a mesh or aweb such as a crushed aluminum filtration material. As illustrated, agap 179 is provided between the first and second filter elements 177,178 to lower a pressure drop through the first and second filterelements 177 and increase the ability to separate oil vapor from thecrankcase gases. In an embodiment, an arrangement of the filter elements177, 178 is set at a 45 degrees from a vertical and a horizontaldirection of flow of the crankcase gases.

FIGS. 4 and 5 illustrate a detailed view of the inlet portion 150 and abottom view of the crankcase breather 124, respectively. As illustratedin FIG. 4, the bottom plate 160 may be provided with one or more troughs180 disposed upstream of the first filter element 177 to collect the oilvapor droplets. Further, one or more drain holes 182 may be provided inthe troughs 180 to direct the oil vapor droplets to flow in asubstantially downward direction. Although, a single row of the troughs180 is illustrated in FIG. 4, in various other embodiments multiple rowsof the troughs 180 may be provided upstream to the first and/or secondfilter elements 177, 178. Moreover, in an alternative embodiment one ormore baffle may be provided in the inlet portion 150 to achieveeffective distribution of the crankcase gases and oil vapor separationbefore passing though the filter elements 177, 178. As illustrated inFIG. 5, the bottom plate 160 is provided with a plurality of drain holes184 positioned below the first and second filter elements 177, 178.

INDUSTRIAL APPLICABILITY

The industrial applicability of the crankcase breather 124 will bereadily appreciated from the foregoing discussion. During the operationof the internal combustion engine 110, the crankcase gases get collectedin the cavity 138 of the valve cover 112 and travel through a two-stagefiltration via the filter elements 177, 178 and enter the oil separator114 provide substantially oil-free crankcase gases at the air intakeunit 118.

The crankcase ventilation system 110 using the crankcase breather 124incorporated within the valve cover 112 for individual cylinder 104 actsas a pre-oil separator before routing the crankcase gases into the oilseparator 114. Further, the crankcase breather 124 disposed within thevalve cover 112 may provide substantial space claim for positioning theoil separator 114 and associated mounting means on the internalcombustion engine 100. Moreover, the presence two filter elements 177,178 provide and additional filtration before the crankcase gases enterthe oil separator 114. In addition to that the sloped troughs 180 withdrain holes 182 upstream of the filter elements 177, 178 allow the oilvapor to get collected and drain downwards under the action of gravity.

The inlet zones 175 only allows substantially unobstructed flow of thecrankcase gases through the crankcase breather 124 may limit therequirements of crankcase breathers 124 to a less number in the internalcombustion engine 100 and effectively relive the pressure in thecrankcase 106.

Although the embodiments of this disclosure as described herein may beincorporated without departing from the scope of the following claims,it will be apparent to those skilled in the art that variousmodifications and variations can be made. Other embodiments will beapparent to those skilled in the art from consideration of thespecification and practice of the disclosure. It is intended that thespecification and examples be considered as exemplary only, with a truescope being indicated by the following claims and their equivalents.

What is claimed is:
 1. A crankcase breather incorporated into an individual valve cover for an individual cylinder, the valve cover forming a cavity and having an crankcase ventilation opening associated with the valve cover, the crankcase breather comprising: a breather body; an inlet portion configured to be in fluid communication with the cavity of the valve cover; and an outlet portion configured to be aligned with the crankcase ventilation opening of the valve cover.
 2. The crankcase breather of claim 1, wherein the breather body includes: a breather top wall; a first pair of breather side walls extending from the breather top wall, the first pair of breather side walls are spaced apart by a first distance; a second pair of breather side walls extending from the breather top wall, the second pair of breather side walls are spaced apart by a second distance lesser than the first distance; and a breather peripheral ledge extending from the first and second pair of breather side walls.
 3. The crankcase breather of claim 2, wherein the crankcase breather further includes a bottom plate coupled to the breather peripheral ledge, and the first pair of breather side walls and the bottom plate define a first filtration chamber and the second pair of breather side walls and the bottom plate define a second filtration chamber.
 4. The crankcase breather of claim 3, wherein the first filtration chamber and the second filtration chamber house a first filter element and a second filter element, respectively.
 5. The crankcase breather of claim 4, wherein the bottom plate includes one or more troughs disposed upstream of the first filter element and one or more drain holes are provided in the troughs.
 6. The crankcase breather of claim 5, wherein the bottom plate includes one or more ear portions extending beyond the inlet portion of the crankcase breather and configured to define an inlet zone within the cavity of the valve cover.
 7. A crankcase ventilation system for an internal combustion engine having a cylinder block that at least partially defines at least one cylinder, the crankcase ventilation system comprising: a valve cover configured to be mounted on an individual cylinder head corresponding to an individual cylinder, the valve cover forming a cavity therein; a crankcase ventilation opening associated with the valve cover; and a crankcase breather incorporated into the valve cover, the crankcase breather including: a breather body; an inlet portion in fluid communication with the cavity of the valve cover; and an outlet portion aligned with the crankcase ventilation opening of the valve cover.
 8. The crankcase ventilation system of claim 7, wherein the breather body includes: a breather top wall; a first pair of breather side walls extending from the breather top wall, the first pair of breather side walls being spaced apart by a first distance; a second pair of breather side walls extending from the breather top wall, the second pair of breather side walls are spaced apart by a second distance lesser than the first distance; and a breather peripheral ledge extending from the first and second pair of breather side walls.
 9. The crankcase ventilation system of claim 8, wherein the crankcase breather further includes a bottom plate coupled to the breather peripheral ledge, and the first pair of breather side walls and the bottom plate define a first filtration chamber and the second pair of breather side walls and the bottom plate define a second filtration chamber having a second volume less than the first volume.
 10. The crankcase ventilation system of claim 9, wherein the first filtration chamber and the second filtration chamber house a first filter element and a second filter element, respectively.
 11. The crankcase ventilation system of claim 10, wherein the bottom plate includes one or more troughs disposed upstream of the first filter element and one or more drain holes are provided in the troughs.
 12. The crankcase ventilation system of claim 9, wherein the bottom plate includes one or more ear portions extending beyond the inlet portion of the crankcase breather to define an inlet zone within the cavity of the valve cover.
 13. The crankcase ventilation system of claim 7, wherein the valve cover includes: a body with a top wall; a pair of side walls and end walls extending from the top wall, wherein the pair of side walls and end walls are joined to form the cavity; a peripheral ledge extending from each of the side walls; and one or more through holes provided on the peripheral ledge and configured to receive fastening members to mount the valve cover on the individual cylinder head.
 14. An internal combustion engine comprising: a cylinder block that at least partially defines at least one cylinder; and crankcase ventilation system for the internal combustion engine, the crankcase ventilation system including: a valve cover configured to be mounted on an individual cylinder head corresponding to an individual cylinder, the valve cover forming a cavity therein; an crankcase ventilation opening associated with the valve cover; and a crankcase breather incorporated into the valve cover, the crankcase breather including: a breather body; an inlet portion in fluid communication with the cavity of the valve cover; and an outlet portion aligning with the crankcase ventilation opening of the valve cover.
 15. The internal combustion engine of claim 14, wherein the breather body includes: a breather top wall; a first pair of breather side walls extending from the breather top wall, the first pair of breather side walls are spaced apart by a first distance; a second pair of breather side walls extending from the breather top wall, the second pair of breather side walls are spaced apart by a second distance lesser than the first distance; and a breather peripheral ledge extending from the first and second pair of breather side walls.
 16. The internal combustion engine of claim 15, wherein the crankcase breather further includes a bottom plate coupled to the breather peripheral ledge, and the first pair of breather side walls and the bottom plate define a first filtration chamber and the second pair of breather side walls and the bottom plate define a second filtration chamber having a second volume less than the first volume.
 17. The internal combustion engine of claim 16, wherein the first filtration chamber and the second filtration chamber house a first filter element and a second filter element, respectively.
 18. The internal combustion engine of claim 17, wherein the bottom plate includes one or more troughs disposed upstream of the first filter element and one or more drain holes are provided in the troughs.
 19. The internal combustion engine of claim 14, wherein the valve cover includes: a body with a top wall; a pair of side walls and a pair of end walls extending from the top wall, wherein the pair of side walls and end walls are joined to form the cavity; a peripheral ledge extending from each of the side walls; and one or more through holes provided on the peripheral ledge and configured to receive fastening members to mount the valve cover on the individual cylinder head.
 20. The internal combustion engine of claim 14, wherein the crankcase ventilation system further comprises an oil separator. 